ITU G.992.5

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ADSL standards

ADSL

ANSI T1.413-1998 Issue 2

G.DMT

ITU G.992.1

G.Lite

ITU G.992.2

ADSL2

ITU G.992.3/4
ITU G.992.3/4 Annex J
ITU G.992.3/4 Annex L

ADSL2+

ITU G.992.5 is an ITU (International Telecommunication Union) standard, also referred to as ADSL2+ or ADSL2Plus.

1 Technical information
2 Deployment
3 See also
4 External links

[edit] Technical information

ADSL2+ extends the capability of basic ADSL by doubling the number of downstream bits. The data rates can be as high as 24 Mbit/s downstream and 1 Mbit/s upstream depending on the distance from the DSLAM to the customer's home.

ADSL2+ is capable of doubling the frequency band of typical ADSL connections from 1.1 MHz to 2.2 MHz. This doubles the downstream data rates of the previous ADSL2 standard of up to 12 Mbit/s, but like the previous standards will degrade from its peak bitrate after a certain distance.

Also ADSL2+ allows port bonding. This is where multiple ports are physically provisioned to the end user and the total bandwidth is equal to the sum of all provisioned ports. So if 2 lines capable of 24 Mibt/s were bonded the end result would be a connection capable of 48 Mbit/s.

[edit] Deployment

[edit] North America

Covad has deployed services across several cities in the United States and now operates the largest ADSL2+ network in the country.

BellSouth has deployed the service in limited areas of its 9 state region.

TELUS in Alberta and British Columbia, Canada; have began the process of activating their networks (03/2007).

Great Works Internet has deployed the service in areas of Maine and New Hampshire.

ColbaNet has deployed the service in the Montreal area of Quebec.

The independent telephone companies and rural carriers of North America probably have the highest total number of ADSL2+ subscribers collectively as they are currently using such technology to deliver the "triple play" voice, video and data services in order to compete with the RBOCs and cable companies with their ILEC and CLEC footprint.

[edit] United Kingdom

Be Un limited [1] is gradually rolling out the service in the UK.
Bulldog Broadband [2] has extensively rolled out this service across the UK.

[edit] The Netherlands

As of october 2005 several wholesale DSL providers (bbned, Tiscali) have ADSL2+ coverage on more than 50% of fixed phone lines in the Netherlands.

[edit] Oceania

Telecom New Zealand is deploying its first ADSL2+ exchange in March 2007, and deploying more after consultation on location.

Many of Australian cities now have ADSL2+ Enabled on their Exchanges. ADSL2+ Services are provided outside the regulated Broadband requirement of the national provider Telstra, so are enabled in areas primarily where there is high interest. Current Service Providers of ADSL2+ in Australia are:

Total Peripherals Group (Otherwise known as TPG)
Telstra (Only in Locations where ADSL2+ Providers already have Equipment)
iiNet
Optus
Adam Internet
Internode
Soul Pattinson Telecommunications

In 2006, Optus announced that it would sell its ADSL2+ network wholesale to other ISP providers. This is currently the most promising option for widespread coverage of ADSL2+ in Australia as the cost to service providers may be prohibitive with many ADSL2+ DSLAMs in each exchange. This move may provide a much wider coverage with cooperation from participating providers.

ADSL2+ Services in Australia are also limited in uptake due to Telstra, who does not allow easy migration from existing Cable/ADSL services to ADSL2+.

Some ADSL2+ DSLAMS in Australia are limited to ADSL2 speeds or slower (Soul Pattinson Telecommunications limit some of their DSLAMs to 10000/1000, Telstra limit their DSLAMS to 20000/1000)